Field of the Invention
The present invention relates to a printing apparatus, a method of controlling the printing apparatus, and a storage medium.
Description of the Related Art
A conventional image forming apparatus has a plurality of print modes for executing print processing, and the print modes include a “standard sheet size print mode,” in which the size of sheets is automatically recognized by a sheet feeding unit of the image forming apparatus, and print processing is performed according to the recognized sheet size. The print modes also include a “user-defined sheet size print mode” (also referred to as non-standard sheet size print mode) that requires a user to set the size of sheets placed on a manual feed tray before printing in the case in which the size of sheets to be used for printing cannot be detected in advance, such as manual feed printing. Because the user-defined sheet size print mode requires the user to input the size of sheets to be used for printing, in order to solve the problem of imposing a burden on the user, some image forming apparatuses have a “free size print mode” that eliminates the need of the user to designate the size of sheets. Japanese Patent No. 3227187 proposes a control method of controlling an image forming apparatus wherein, in the case of the free size print mode, print processing is performed on the first sheet of paper during which the size of the first sheet is recognized based on the paper feeding speed and the result of detection performed by a sensor, provided along a conveyance path so as to determine the sheet size, and the sheet size recognized during printing on the first sheet, is used to perform print processing on the second and subsequent sheets.
In order to carry out the print processing described in Japanese Patent No. 3227187, it is necessary to delay the timing of issuing an instruction to start a sheet feed operation for feeding the second sheet and the timing of the start of processing on image data to be printed on the second sheet until the result of recognition of the size of the first sheet is obtained after the printing processing on the first sheet has been finished. For this reason, there is a problem, in that in the print processing on the second and subsequent sheets, a sheet feeding start instruction is transmitted late to the sheet feeding unit, which increases the time required until completion of printing of an image on the second sheet. In addition, image data to be printed on the second and subsequent sheets need to be processed according to the result of recognition of the size of the first sheet, and an image processing unit that performs image processing may have to perform trimming on the image data depending on the recognized sheet size. In this case, if the image processing unit does not have an image trimming function, the control method described in the patent literature is problematic in that it is not possible to designate the free size print mode.